February 1st, 2012
Originally posted here
It’s easy to list the reasons why we are supposed to love urban agriculture: the food it yields is fresh and local; the farming it requires is fun and social; the effect on neighborhoods is revitalizing and healthy. Critics point to its inability to replace existing production and distribution channels for produce, but what if its impact extended beyond the small farm or immediate community?
What if it could solve other problems? One of New York’s greatest environmental challenges is its combined sewage overflow (CSO) problem. Our outdated sewer system is designed to collect stormwater runoff, domestic sewage, and industrial wastewater in the same pipe on its way to a sewage treatment plant. When the rain is heavy, though, volume exceeds capacity and untreated wastewater flows right into our waterways.
Green infrastructure is a term that refers to a wide range of technologies and systems to improve water quality through the capture and reuse of stormwater. But the policies that incentivize green infrastructure and those that govern urban agriculture are not coordinated. In some cases, urban agriculture is actively excluded from official definitions of green infrastructure.
In an effort to support farming in the city and help scale it up, Tyler Caruso
and Erik Facteau
set out to prove scientifically the environmental benefits of rooftop and other urban farms, in particular their ability to manage stormwater, with their research project Seeing Green
. In describing this project, Caruso and Facteau touch on issues that range from the effect of scientific research on public policy, the shift towards a definition of sustainability that includes performance alongside design, and the need to layer different registers of analysis in efforts to bring about a city that is more responsive to natural systems.
What is Seeing Green and how did it come about?
: Seeing Green
is a research project that studies specific urban agricultural sites in the New York City area in order to demonstrate how urban agriculture should be considered as a viable and important component of a city’s green infrastructure. One of the sites we’re currently looking at is Brooklyn Grange
, a rooftop farm in Long Island City; another that we will be looking at is Added Value
, a raised bed farm in Red Hook. We’re also looking at the rooftop farm atop the Parks Department’s Five Borough Administrative Building
on Randall’s Island.
By measuring evaporation and evapotranspiration
rates, we are looking to create metrics to calculate how much water urban farms are managing, through both detention (meaning the temporary storage of excess stormwater) and retention (the indefinite storage of excess stormwater). This will tell us how much water urban farms keep from entering the sewer system, therefore reducing combined sewer overflows.
When you start to get these numbers, you can begin to extrapolate over larger areas of land – whether it’s exisiting farms or underutilized land with farming potential – to determine how much water can be managed and what the best practices are for doing so. Right now, we are looking at a couple different sites as a base line and moving forward from there.
: This project began as a graduate research project and as it has evolved to include a series of interesting collaborations; and the sponsorship of the Open Space Institute has helped us pursue these partnerships. In one project, called “Farming Up,
Alec Baxt and Lise Serrell look at nutrient quality of crops growing in urban environment compared to rural environments. “Don’t Flush Me
” is a project that puts sensors in sewage outflow points and notifies individuals about how much wastewater they produce during and immediately after those weather events that cause sewage to overflow into the harbor. Another one is called “Farming Concrete
,” for which Mara Gittleman has been calculating the area, weight and monetary value of food grown in community gardens in New York City.
: Another project we’ve been involved in has been to set up a demonstration project on the roof of the Association for Energy Affordability
‘s headquarters in the Bronx. We emulated the green roof condition on part of the roof and installed a container underneath so we could measure the amount of water running through the green roof and then compare that to the amount of water rushing off the impervious surface of the regular rooftop.
: If you take all of these metrics and you collapse them – you look at the nutrient level of both the soil and the crop, you look at the stormwater management potential, the energy rate reduction, the food production potential — the combined analysis is much more powerful. The guiding idea is this: if you can first define the benefits and know what they are and research them, then you can quantify them, and then you can monetize the benefits — and that’s when it really becomes valuable to private property owners and cities. At that point, the research can begin informing policy. And it can begin informing the development of best management practices around the design of farms. For example, if we observe nutrient run-off, we can help design small wetlands around the drain. If we know how much water an urban farm can manage at a particular soil depth, and how much productivity and costs would be affected by increasing its depth, then we can inform building owners about the best investment to reach the desired productivity and the desired environmental outcomes. It’s a necessary step if we want to see urban agriculture grow in New York City.
How did you both get involved in this topic?
: My background is in microbiology and mycology, working mostly on plant restoration projects and the symbiotic relationship between fungi and plants. I studied environmental science and forestry in college. And I met Tyler while in the graduate program in environmental systems management at the Pratt Institute.
Before this, I was working on landscape design and urban agriculture projects and designing and installing grey water systems in San Francisco. When Erik and I started the discussions that eventually led to Seeing Green, we were looking for a thesis project and decided to work together. At the time, there were lots of projects around that dealt with urban agriculture, and most of them were primarily concerned with the economic or social benefits. They might mention the environmental benefits of farming in the city, but not in great depth. The potential of urban agriculture as green infrastructure was a connection that hadn’t yet been made. In 2010, we started noticing how much City agencies were talking about green infrastructure, and realized that if we wanted our cities to support urban agriculture under the banner of green infrastructure, we would have to quantify the environmental benefits.
: The green infrastructure documents from the City that we were looking at all seemed to focus on traditional green roofs. So we started researching how much water these systems could actually handle while simultaneously looking at how rooftop agricultural projects are performing.
: The grants that Erik is referring to include a green roof tax credit incentive, issued through the Department of Buildings, that specifically prohibits urban farms because of plant selection and because of speculation that irrigation – traditional green roofs don’t require irrigation; agricultural green roofs do – would make rooftop farms less able to retain stormwater than a traditional green roof. That’s a clear example of the city implementing progressive green infrastructure policies that exclude urban agriculture. And in this case, the policy is based on hypotheses that are scientifically untested.
We also find the language of these policies to be more prescriptive than performative. Our methodology for the Seeing Green project looks closely at performativity
: how well urban farms and green infrastructure perform over time.
What kinds of tools or precedents were out there to help you analyze, monetize, to quantify or identify proper metrics?
I know everyone says this, but I think social media – Twitter, Facebook, etc. – has really helped empower people with a DIY attitude, has helped citizens’ groups to form, has helped individuals collaborate with a science lab.
Platforms like Kickstarter have created more of a sense of “we’re all in it together,” and that attitude has definitely benefited us.
: Kickstarter was a huge help in getting this off the ground. We had worked out our methodology as part of our thesis project at Pratt, and when we finished that we asked ourselves, “Where do we go from here?” We knew the equipment that we needed, and we knew that farmers and communities would really value the information we wanted to collect. So we used Kickstarter not only to raise money for equipment but also to raise awareness. Groups from England, from Australia, from the west coast contacted us because of their interest in the research.
: I just spoke to someone preparing a research report on the potential for urban agriculture in San Francisco. Another group in Minneapolis recently requested our collaboration on a large-scale urban agriculture initiative out there. Around the country, and the world, it’s a really supportive community. There are also some big research initiatives right here in New York….
Like “Five Borough Farm,” which Urban Omnibus featured last year. That effort is also trying to push the idea of metrics.
: Exactly. I think one of Five Borough Farm’s contributions to the field is its focus on the public health perspective. There’s also the work Kubi Ackerman is doing at Columbia’s Urban Design Lab to evaluate New York’s capacity for urban agriculture. We’ve used some of his preliminary numbers to help us make the case that if we have x
amount of stormwater, and if we extrapolate from the knowledge of how many vacant lots or rooftops could be used to scale up urban agriculture, then we can start to talk about how to address the combined sewage overflow problem. If we know that we could manage this many gallons through urban farms, and how much money the city spends per gallon on treating stormwater and wastewater, then we can calculate how much money the city could save if urban agriculture were considered one of many pieces of the green infrastructure puzzle. When you compare that to the cost of retrofitting or constructing new sewage treatment plants, and factor in the amount of energy that goes into treating wastewater, the savings become astronomical. Plus, there are all the benefits that urban agriculture advocates have made well known: vacant land is being re-utilized by communities, increasing property values, supporting economic micro-enterprises, contributing to healthy living, decreasing public health costs. Once you start layering all those factors, the potential of these farms or community gardens is phenomenal.